Extracted JS and CSS sections into new files 'BaseJS.vm' and 'AppJS.vm' so...

Extracted JS and CSS sections into new files 'BaseJS.vm' and 'AppJS.vm' so they can be included in other templates without other unnecessary scripts and stylesheets; Created new 'Basic.vm' layout with no XNAT content and 'Content.vm' as a container for XNAT data available through Velocity that can be retrieved via AJAX without pulling in conflicting scripts and stylesheets; Added sample templates 'Basic.vm' and 'Blank.vm' for use with the 'Basic' and 'Content' layouts respectively.